High School SMILE Meeting
15 November 2005

Bill Blunk (Joliet Central HS, retired)             Original Tom Lehrer Songs
Using his laptop Bill played  some of Tom Lehrer's math songs from an original 1951 wire recording.  These songs can be obtained from these websites:

Thanks, Bill.

Bud Schultz  (Aurora Middle School)              Ancient Matches
Bud started talking about temperature, a topic he covers in his various science classes (see also his handout). Bud's students often ask why we define and measure temperature the way we do. When posed with this question Bud has the students do a thought experiment with a balloon: as it is cooled in a freezer, it shrinks; as it warms up again it gets bigger. This correlates with a decrease and then an increase in the kinetic energy of tje air molecules in the balloon. He found that one experiment particularly excited the interest of his students: the "Fire Piston" (as Earl pointed out, is also known as a Fire syringe).  (See the website http://www.onagocag.com/piston.html). American Educational Products LLC also sells a great version of it: http://www.shnta.com/Product/Science/3572.htm . The fire piston is really an ancient device, but Bud showed us his newer version:. a glass, cylindrical tube with its bottom end closed off. As we watched, Bud placed a small (dime sized) piece toilet tissue in the bottom of the tube.  He then held up a rod (about 25 cm long) with a piston at its end.  The piston was fitted with O-rings.  Holding the rod, he slid the piston into the top of the tube.  With the lights dimmed, Bud ran the piston down into the tube as hard and quickly as he could.  There was a bright flash of light at the bottom of the tube!  Amazing! We then could see that the tissue had ignited and burned.  By rapidly (and adiabatically) compressing the air in the tube, the air temperature was raised high enough to ignite -- reminding us of Ray Bradbury's novel Fahrenheit 451.   Bud told us that this really galvanized his students to ask a lot of questions, and take a real interest in trying to understand how it works.  Thanks, Bud!

Larry Alofs  (Kenwood HS, retired)           LED's, etc.
Larry
handed out copies of  a Bill Amend classic "Foxtrot" comic strip from November 6, 2005, in which Jason presented a numerical word search (or nerdsearch): http://www.livejournal.com/community/comic_foxtrot/66515.html?mode=reply. The clues were various terms, integrals, derivatives, sums, etc. One of the questions involved the sum of squares of the first 47 integers, which is a special case of the expression

S(n) = 12 + 22 + 32 + . . . + n2
for n=47. One can show by induction that
S(n) = n (n + 1) (2 n + 1) / 6
The answer is correct for n=1; S(1) = 1. Assume that the answer is correct for the integer n. Then
S(n+1) = S(n) + (n+1)2 = (n+1) ( n (2n+1)/6 + (n+1)) = (n+1)/6 ( 2 n2 + n + 6 n + 6)
= (n+1)/6 ( 2 n2 + 7 n + 6) = (n+1)/6 (n+2) (2n+3).
Thus the result is true for n+1. For the specific example we have
S(47) = 35720 . . . S(48) = 35720 + 482 =38024
This is a really neat way for students to hone their skills in various areas of mathematics to which with they may have been exposed. 

Larry showed us some LED flashlights, a type of flashlight for which he is an enthusiastic proponent. White LED's need enough cells to provide more than 3.5 Volts (eg, three individual cells are required). Larry then showed a flashlight with a white LED that works with a single cell (1.5 volts). So how do they get the voltage high enough to run the flashlight?! Larry was not sure, but one possibility is a Voltage Multiplier circuit (see http://www.voltagemultipliers.com/html/multcircuit.html), which uses capacitors and diodes in series.  Larry made an analogy with the movement of water up a pipe against gravity (increasing its potential energy) using one-way valves separating segments of a pipe and a device that can simultaneously squeeze a section of the pipe and expand the section of the pipe just above the squeezed section. Very slick! Thanks, Larry!

Brenda Daniel (Fuller School)            Fire Safety
Brenda
had a handout (from the Chicago Sun Times Nov 18, 2005) for us which she passed out to begin her presentation. The handout came from free Sun Times copies given out to 4th graders in Brenda's class. Both the Chicago Sun-Times (on Tuesdays) and the Chicago Tribune (on Mondays) provide free papers to students, which often contain useful/interesting articles on science. The newspaper article covered general topics in fire safety, topics relating fire safety and electricity, and safety activities for home and school, and provided a quiz for the students to take to test their fire safety knowledge. Brenda's class also had a visit from firemen who demonstrated an infrared detecting device, which, by detecting body heat, helps the firemen find trapped victims in a fire. Neat!  Thanks, Brenda.

Ed Scanlon (Morgan Park HS, biology)            Evolution
Ed
started with the following handout:

The questions on Ed's list ask what makes humans different from other organisms. Continuing, classification of organisms into groups is based (mostly/historically) on similarities among organisms; but what makes one species (e.g., us) different from another species (e.g., apes)? So after discussing the first handout, Ed hands out a condensed version of a probable family tree for humans with a list of characteristics that primates share and another list of characteristics peculiar to humans. Regarding the latter, our foramen magna (openings in skull for the spinal cord) point straight down, our legs are relatively much longer than our arms, etc. Pat Riley pointed out that our "complete package" of characteristics is perhaps what makes us really different from other species.  This led to an extremely lively discussion of evolution, creationism, and "intelligent design".  Thanks for the info, Ed!.

Don Kanner (Lane Tech HS, physics)                Any Questions?
Don
showed a strategy for getting class participation.  He handed out a card to each student.  When students asked a question or gave an answer (after being called on), he stamped their cards.  At the end of class, the students put their names on their card, and Don collected them.  Each stamp on the card was worth extra credit on a future examination. Students quickly took an interest in class discussion.  Don illustrated the strategy using two balloons containing Helium gas.  We asked the following questions:

  1. Why are the 2 balloons repelling? (like charges repel)
  2. Why are the balloons floating in air? (anti-gravity shields? -- ha)
  3. How do we know that Helium is in the balloons? (Don inhaled Helium from the balloon and then spoke in a high-pitched voice.)
The students appreciated getting credit for their participation.  Good ideas!  Thanks, Don.

Khara Criswell (Juarez Community Academy)          Music
Khara brought a small boom box and a long list of "Songs for the Science Classroom", such as "Ring of Fire" by Johnny Cash. Every time Khara does a lab she brings in a CD mix with music/songs that relate to the experiment (e.g., in chemistry, physics, etc.). For "Black Magic Woman" by Santana, Khara has an activity in which there is a mix of chemicals that turn from white to black and finally to purple. Khara recommended these websites:

Chemistry Songs:  http://www.delta.edu/slime/chemsongs.html and http://www.delta.edu/slime/chemsongs.html
Physics Songshttp://www.haverford.edu/physics/songs/
Neato!  Thanks, Khara!

Ann Brandon (Joliet West HS, retired)            Strange Temperatures on Shipboard
Ann
recently made a voyage through the Panama Canal, on which there were daily weather reports.  She was struck by some of the temperatures:  57 °C = 14 °F and 69 °C = 20 °F.  Very strange temperatures --- even for the tropics!  Thanks, Ann.

The following people could not present lessons today, because we ran out of time. They will be scheduled first at our next SMILE meeting, Tuesday November 29. See you there!

Notes prepared by Ben Stark and Porter Johnson.